code: def test_reservation_environment_not_exists_start_listening_socket_return_socket(
      self,
  ):
      tfos_server = Server(1)
      print(tfos_server.start_listening_socket().getsockname()[1])
      assert (
          type(tfos_server.start_listening_socket().getsockname()[1])
          == int
      )
  
file_path: TensorFlowOnSpark/tests/test_reservation.py
imports: import os
  import threading
  import time
  import unittest
  from tensorflowonspark import util
  from tensorflowonspark.reservation import Reservations, Server, Client
  from unittest import mock
label_desc: Use image node_id 6 for calling the ReservationTest obj's underlying member method code with example usage: obj.test_reservation_environment_not_exists_start_listening_socket_return_socket() without return types